Refrigerating process and apparatus



3y 1, 1930. R. w. DAVENPORT 1,769,113

REFRI(FrERA'IINCr PROCESS AND APPARATUS Filed Aug. 3, 1926 I N V EN TOR.Famsom 14/. 0a ven p or 7 A TTORNE Y.

Patented July 1, 1930 UNITED STATES PATENT OFFICE RANSOM W. DAVENPORT,OF DETROIT, MICHIGAN, ASSIGNOR TO CHICAGO PNEUMATIC TOOL COMPANY OF- NEWYORK, N. .Y., A CORPORATION OF NEW JERSEY REIBIGEBATING PROCESS ANDAPPARATUS Application filed August 3, 1926. Serial No. 126,782.

This invention relates to processes and apparatus for producing heattransforming effects with particular reference to closed cycle systemsutilizing lubricating Working substances of the type disclosed in mycopending application Serial No. 60,311 filed October 3, 1925, anddistinguishes in certain important respects from m previously disclosedmethods and means or producing refrigeration with a lubricatingrefrigerant whose physical constitution resembles a solution of viscousand volatile liquids, as set forth in my copending applications, SerialNo. 85,580 filed February 2nd, 1926; Serial No. 88,164 filed February15th, 1926; Serial No. 95,531 filed March 18, 1926; Serial No. 106,825filed May 5th, 1926; and Serial No. 106,826 filed May 5, 1926.' Theseprevious disclosures all involve the concentrating or thickening of theworking substance for lubricating purposes and the feeding of thethickened liquid to the pump. Such feeding of the lubricatingconcentrate, however,

is substantially continuous and is effected largely by gravity so thatthe pump) necessarily must be on a lower level or eneath the evaporatorcontaining the working substance. 4

One object of the invention is to devise processes and apparatus forutilizing lubricating refrigerants Without restriction as to theposition of the pum relative to other parts of the apparatus. otherobject is to permit the eriodic return of the concentrated solution toortowardsthe ump.

Other objects will be apparent from t e de-' tailed description of theinvention which follows.

In carrying out the present invention the ste common to my previousdisclosures which involves the returnin of the concentrate to the pumpis also per ormed, but in a different manner and by means of differentapparatus, so that the usual machine unit which contains the pump may beplaced above the evaporator if desired. My improved process contemplatesperiodically interrupting the withdrawal 0 the vaporized worklngsubstance from the concentrating chamber in order to draw concentratetherefrom for lubricating purposes. The change in the fluid'beingwithdrawn is effected in alternation and entirely automatically. Theautomatic regulation ma be controlled by the variations of the liquidlevel in the concentrating chamber and the change is preferablyinstantaneous. The concentrated lubricating 'liquid'which is withdrawnmay be passed directly to the pump or other pressure reducing device ifthe latter is adapted to handle surges of liquid, or'it may be storedand fed in small amounts. The invention further comprises suitableapparatus for practicing the improved process.

In order to illustrate the invention and the manner of its use one formand arrangement of apparatus is shown in the accompanying drawings inwhich:

Fig. '1 is a view largely diagrammatical in character of a refrigeratingsystem; and

Fig. 2 is a view on an enlarged scale'partly in section and partly inside elevation of the automatic. control apparatus.

The apparatus diagrammatically indicated in Flg. 1 for practicing myimproved process consists essentiall of an evaporator A disposed inthe'f'zone rom which heat is to be extracted as in the storagecompartment of a refrigerator, a pump or compressor B and a condenserC,these parts being connected together to form a closed cycle system.The parts with the possible exception of the evaporator A may be of anysuitable or desired type, a prime mover 0 some kind (not shown) beingnecessary to drive pump B.

Evaporator A terminates in-a concentrating vessel A, the outlet a of theevaporator proper being disposed adjacent the top of concentrator A soas to permit a body of J spaced from the bottom of tinct from conduit Dit is shown as connect- I.

ing with conduit D at point d adjacent pump B. Condenser C connects withevap-' orator A through a conduit F controlled by a valve or expansiondevice G of any suitable or desired type.

The s stem is arranged to operate with a lubricatlng working substanceconsisting of a mixture of a volatile liquid and a lubricant, such asdisclosed in my aforementioned copending application, Serial No. 60,311filed October 3, 1925. A typical working substance is methylene chloridehaving grease in solution in the proportions of 85% methylene chlorideand 15% grease. A body of this liquid mixture is placed in evaporator Aand in the concentrator chamher A. On starting pump B, it will beevident that the-gaseous contents of the eva orator AA including thevapor of the wor 'ng substance will be withdrawn through both conduits Dand E if the same are open and if the body of liquid is at or about thelevel indicated at w. With the proper amount ofworking substances in thesystem, the concentrated lubricant will gradually accumulate inconcentrator A raising the level of the liquid therein above the openingto conduit E whereupon the vapor of the working substance will continueto be drawn off through conduit D.

With the liquid level standing above the 0 ening to conduit E, it willbe evident that ii the opening to conduit D is closed the entire suctioneffect of. pump B will operate through conduit E to draw liquid fromconcentrator A and discharge it into pump B. The means for restrictingor closing the vapor line while the concentrate is being sucked up arepreferably'automatic in operation. Such means may comprise a floatcontrolled by the level of the liquid in concentrator A operating a snapvalve disc on to and oil the vapor pipe inlet when the liquor isrespectively high and low in level. The variation in the level may begreat so that the liquid is drawn away only at rare intervals, orsmall,.in which event the liquid will be drawn away more frequently.

In the form' shown conduit D carries adjacent its extremity a collar 3having projections or ears 4 (Fig. 2) in which is mounted a shaft orpivot- 5. A float-member 6 is mounted upon pivot 5, also a closure plate7 for the open end of conduit D. Float member 6 is arranged to operateclosure 7 with a snap action by means of a coiled spring 8 secured atoneend to member 6 at a point 9 s aced from pivot 5 and at its other end toc osure 7 adjacent the outer extremity ofthe latter. By suitabledisposing members 6 and 7 relative to each other and b connecting thespring, 8 thereto at suita le spaced points member 6 will throw valve 7in response to predetermined variations in the level of the liquid inconcentrator A. With the arrangement shown closure valve 7 will openwhen the liquid level is at w and close when the liquid is at y. Withthe float in its lower position and valve 7 open, the pull or lie of thespring 8 is indicated bythe full line indication of the spring in Fig. 1and by the broken line m in Fig. 2. With the rise of the liquid to the ylevel the position of the float is indicated in broken outline in Fig. 1and in full lines in Fig. 2, the pull of spring 8 upon the open valvethen being indicated by broken line at (Fig. 2). This causes the valveto move toits closed or full line position shown in Fig. 2. With thefall 0 the liquid level to a: the inclination of the-float is indicatedin full lines in Fig. 1 and in broken lines in Fig. 2. The pull ofspring 8 upon the closed valve indicated by broken line 0 (Fig. 2 issuch as to cause the valve 7 to move to open position. A stop 11 may beprovided to fix the extent of opening of valve 7. With the parts so fardescribed it will be'apparent that when the system is in operation thegaseous and the liquid contents of concentrating chamber A are withdrawnby pump B in alternation. The periods during which conduit D is open forthe withdrawal of vapor are preferably longer than the periods duringwhich conduit E is receiving the total suction effect of the pump towithdraw li uid, a proper arrangement and adjustment 0 the float controlmechanism being efiective to establish the duration of such periods andthe quantity of liquid withdrawn at any one time.

If pump B is not adapted to handle surges of liquid such as will resultwhen conduit' D is closed, or if the lubrication of the pump will bebetter accomplished by a gradual feeding of the concentrate, suitablemeans may be provided for storing the liquid withdrawn from chamber Aand erinitting it to pass in limited amount to t e pump. One manner ofeffecting this result is shown in Fig. 1 wherein conduit E .isenlargedat E to form a chamber in which is positioned beneath the open end ofthe conduit a receptacle E for the li uid concentrate. This receptaclemay be o any desired size so as to hold the entire charge or only a partthereof and the bottom of the receptacle is formed with a small openingas'indlcated to .permit a dribble of liquid into the conduit the liquidpasses oif as vapor leaving the prises disposing a body of the workingsubconcentrated lubricant to be periodicallyrestance in the zone fromwhich heat is to be moved through pipe E. While the invention extracted,reducing the pressure on said body is applicable to conventionalrefrigerating to produce vaporization of the volatile liquid systems, inwhich the working substance is so .as to cause a heat absorbing effectand vaporized by straight pumping, it has parto concentrate thelubricant, periodically ticular-application to closed cycle systemsstopping the removal of vapor to withdraw operating on thevapor-gas'principle as disconcentrate for lubricating purposes,returnclosed in my copending application, Serial ing the withdrawn fluidto said bod after No. 15,172, filed March 19, 1925. Fig. 1illuscondensing the vapor and diluting t e con trates either systemsince the characterof centrated lubricant with the condensate, and thefeeding device G determines the operat controlling the periods of vaporand liquid ing characteristics of the system. If devicewithdrawalautomatically in response to G is arranged to passliquid only,the sys: variations in the level of said body.

tem operates in the conventional manner by to pass a stream of gas,vapor and liquid the liquid and a lubricant, the process of refrigsystemoperates on the vapor-gas principle. eration which comprises disposin abody of The vapor-gas arrangement eflects a greater the liquid mixtureinthe zone'o? refrigeraconcentration of the lubricant since the contion,withdrawing in alternation first the tents of the evaporator chamber Eunder vapor of the liquid and then the liquid itthis s stem are drawnoif at approximately self, the former to cause absorption of heat thehlghest temperature obtaining in the and to effect concentration of theliquid and chamber in which evaporator A. is mounted the latter forlubricating purposes, storing rather than at the relatively low uniformthe withdrawn liquid and feeding it contemperature of the, workingsubstance as stantly in limited amount to the parts rein conventionalsystems. quiring lubrication, condensing the vapor,

With the arrangement herein disclosed the diluting the liquidwith thecondensate, and vapor conduit is normally wide open and no. returningthe liquid so diluted to said body. loss of efiiciency through wiredrawing is, 4.-. In a closed cycle system utilizing as a occasioned. Yetthe machine unit which inworking substance a mixture of a volatilecludes the pump may be at any reasonable liquid and a lubricant, theprocess of refrigheight above the evaporator since the full erationwhich comprises disposing'a bod of pressure difference of the two sidesof the the liquid mixture in the zone of rerigsystem is available tolift the concentrate. eration,'withdrawing in alternation first theWhile the process and apparatus aspects vapor of the liquid and then theliquid itof the invention have been described in what self, the formerto cause absorption of heat is now considered to be their preferred andto effect concentration of the liquid and forms, it is to be understoodthat the inthe latter for lubricating purposes, storing vention is notlimited to the specific details the withdrawn liquid and feeding itconthereof but covers all changes, modifications stantly in limitedamount to the parts reand adaptations within the scope of'the apquiringlubrication, condensing the vapor,

pended claims. diluting the liquid with the condensate, re-

I claim asvmy invention: turnlng the liquid so diluted to said body, 1.The process of refrigeration with a and controlling the periods of vaporand working substance consisting of a volatile liquid withdrawalautomatically in response liquid and a lubricant in solution which tovariations in the level of said body.

comprises dis osing a body of the working 5. In a refrigerating system,in comblnasubstance in t e zone from which heat is to ,tion, anevaporator for containing a liquid be extracted,reducing the pressure onsaid to be evaporated, a pump, a plurality of .body to producevaporization of the volatile fixed connections between said pump andliquid so as to cause aheat absorbing effect said evaporator, meanscontrolling at least and to concentrate the lubricant, periodione ofsaid connections to cause said cally stopping the removalof vapor towithto withdraw either the gaseous or the iqui draw concentrate forlubricating purposes, contents of said evaporator, and a condenserreturning the withdrawn fluids to said body rc elving thedlscharge fromsaid pump and after condensin ,the vapor and diluting the directing thesame to said evaporator. concentrated lu ricant with the'condensate, 6;In a refrigerating system, in comblnaand controlling the periods ofvapor and 51011, an evaporator forcontamlng a liquid liquid withdrawalautomatically in response t be eyaporated, a pump, a plurality of to theoperating characteristics of the fixfid nnectlons be ween saldpump andsystem. said evaporator, me ans controlling at least 2.The -process ofrefrigeration with a one of said connections so that said pump workingsubstance consisting of a volatile withdraws the gaseous contents ofsaid liquid and alubricant in solution which comevaporator for a givenperiod and then 3. In a closed cycle system utilizing as astraightpumping. If device G is arranged .working substance a mixture of avolatile withdraws liquid only from said evaporator, and means forremoving heat from the liquid and vapor discharged from said pump beforereturning the same to said evaporator.

7. In a refrigerating system, in combination, an evaporator forcontaining a liquid to be evaporated, a pump, connections from said pumpto said evaporator so arranged that one draws liquid and the other gas,means operating with a' snap action automatically at intervals to causesaid pump to withdrawfrom said evaporator. in alternation either thegaseous or the liquid products thereof, and a condenser in theconnection from said pump to said evaporator.

8. In a refrigerating system, in combination, an evaporatorfoncontaining a liquid to be evaporated, a pump, connections from saidpum to said evaporator so arranged that one rawsliquid and the othergas, control means for'at least one of said connections operatingautomatically with a snap action in response-to changes in the level ofthe liquid in said evaporator for causing said pump to withdraw inalternation from said evaporator either the .gaseous or the liquidproducts thereof, and condensing means in the connection from said pump-to said evaporator.

9. In a refrigerating system, in combination, an evaporator containing arefrigerant solution, a pump, a connection from sa1d pump to saidevaporator for gas, a. connection from said pump to said evaporator forliquid, a valve for closing-said gas connection, means for effecting aquick action of said valve, and connecting means including a condenserfrom said pump to said evaporator.

10. In a refrigerating system, in combination, an evaporator containinga refrigerant solution, a pump, a connection from said pump to saidevaporator for gas, a connection from said pump to said evaporator forliquid, a valve for closing said gas connection, a float devicecontrolled by the level of said solution, means connecting said deviceto said valve arranged to be offcentered by the movement of said deviceto throw said valve with a snap'action, and a connection from said pumpto said evaporator including a condenser.

11. In a heat transforming system the combination with a concentratingevaporator containing a lubricating refrigerating solution, of a pumpadapted to evaporate and to be lubricated by said solution,aconnectionbetween said pump and said evaporator for vapor, a connectionbetween said pump and said evaporator for liquid, control means for oneof said connections with in evaporator and operating automatically'witha snap action in response to the operating conditions of the system, anda return connection from said pump to said evaporator including acondenser.

12. In a heat transforming system the combination with a concentratinevaporator containing a lubricating refrigerating solution, of a pumpadapted to evaporate and to be lubricated by said solution, a connectionbetween said pump and said evaporator for va'por, a connection betweensaid pump and said evaporator for liquid, means comprising a floatcontrolled by the liquid level in said evaporator acting to close saidvapor connection while said liquid level is between predeterminedlimits, and a condenser forming a part of the return connection fromsaid pump to said evaporator.

13. In a refrigerating system, in combination, a concentratingevaporator containing a lubricating refrigerant solution, a pump adaptedto evaporate and to be lubricated by said solution, means whereby saidpump withdraws either vapor or liquid from said evaporator, means forfeedin the liquid withdrawn by said pump in limited quantity to saidpump to lubricate the same, and means including a condenser forreturning the discharge of said pump to said evaporator.

14. refrigeranting system comprising a concentrating evaporatorcontaining a lubricating refrigerating solution, a pump, a connectionfor vapor from said evaporator to said pump, a connection for liquidfromsaid evaporator to said pump, means operating automatically andperiodically to close said vapor connection, means in said liquidconnection for storing liquid and feeding it at a predetermined rate tosaid pump, and a connection from said pump to said evaporator includinga condenser.

15. A refrigerating system comprising a concentrating evaporatorcontaining a lubricating refrigeratlng solution, a pump, a connectionfor vapor from said evaporator to said pump, a connection for liquidfromsaid evaporator to said pump, means controlled by the level of thesolution in said evaporator for automatically and periodically closin Isaid vapor connection, a receptacle in sa1d liquid connection forintercepting and storing liquid withdrawn from said evaporator, saidrece tacle having a restricted opening for ceding the liquid at apredetermined rate to said pump,

and a connection from said pump to said evaporator including acondenser.

Signed by me' at'Detroit, Wayne County, Michigan, this 30th day of July,1926.

RANSOM W. DAVENPORT.

